Current semiconductors and other similar devices are often manufactured with a large number of fuse elements which are used to invoke the replacement of failing cells or components, and provide direct alternative current (DAC) trimming, etc. During testing of the device, selected fuses are usually blown by either a laser beam or an electrical current, depending on the design of the fuse/device. In an electrical fuse design, electronically programmable fuses are blown by passing a current through the fuse link. The electrical current then causes a permanent change to the resistance of the fuse. The fuses that are blown are selected by one or more programming methods, which are generally known to those skilled in the art.
One-time electrically programmable fuses, also called e-fuses, have become very popular recently, because of the circuit and systems design flexibility that it provides; the e-fuse can be programmed even when the chip is mounted in the package and installed in the system. For example, customers can tailor a design to the specific needs of the application after the product is installed in the field. The e-fuse also enables the freedom to alter the design, or fix any problem that may occur during the life of the product.
The one-time electrically programmable fuse is much smaller than ablative type fuses, resulting in circuit density advantages. Although e-fuses provide the above-mentioned benefits, integration with standard complementary metal oxide semiconductor (CMOS) processing has been problematic. Furthermore, obtaining a tight distribution of blow voltages derived from normal operating voltages continues to be challenging.